Epithelia vaginal epithelium

Vaginal Rings. Vaginal epithelium is readily permeable to contraceptive steroids. Since the vascular drainage of the vagina bypasses the Hver, this route of adrninistration potentially permits utilisation of dmgs that have low oral activity. 

Eroschenko VP, Osman F. 1986. Scanning electron microscopic changes in vaginal epithelium of suckling neonatal mice in response to estradiol or insecticide chlordecone (Kepone) passage in milk. Toxicology 38 175-185. 

Brittebo EB, Kowalski B, Brandt I. 1987. Binding of the aliphatic halides 1,2-dibromoethane and chloroform in the rodent vaginal epithelium. Pharmacol Toxicol 60 294-298. 

The animals treated with 200, 400, and 800 lU A showed a healing effect of vitamin A on the cornified vaginal epithelium as early as 2 days after starting the experiment. In the smear of all concentrations, almost exclusively leukocytes — indicating a successful healing and mucosal regeneration — with only sporadic epithelial cells and squamous cells... 

The drug is concentrated in estrogen target tissues, such as the ovaries, uterus, vaginal epithelium, and breasts. Hydroxylation and glucuronidation of the aromatic rings are the major pathways of metabolism excretion occurs primarily in the feces. 

Induction of certain changes in the vaginal epithelium and secretion. 

Little is known of any regidation of the metabolism of sialic acid on a level higher than the enzymic level just described. The few experiments performed with animals point to an influence exerted by hormones. Thus, increase of the synthesis of sialoglycoeonjugate (mucus) has been described as occurring in mouse vaginal-epithelium under the influence of estrogen.240 Similarly, insulin therapy restored the sialic acid content of rat hepatocyte-membrane which was decreased in streptozotocin-induced diabetes.241... 

In whole-body autoradiographic studies, covalently bound radioactivity from ethylene dibromide was detected in the surface epithelia of the entire respiratory and the upper alimentary tracts of mice and rats (Brandt, 1986), in the epithelia of the oral cavity, oesophagus and forestomach of fetal mouse (Kowalski et al., 1986), and in vaginal epithelium of mice and rats (Brittebo et al., 1987). 

Is a local or systemic effect required This will influence, for example, the choice between a traditional dosage form, such as a semisolid cream or gel, and a system that promotes increased intravaginal residence, with a concomitant increased possibility of absorption across vaginal epithelium, for example, from intravaginal ring (IVR) systems or systems utilizing a bioadhesive polymer component. 

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